Article Title

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Abstract

T. L. Tusa Jr. & K. J. Prelgo Bethel University, St. Paul, MN

Purpose: Motor imagery (MI) is a complementary mental practice that has been determined to be beneficial when performing musculoskeletal rehabilitation or sports performance programs. The more motor units recruited, the greater the central nervous system activation, neural innervation and potential for musculoskeletal and neuromuscular development. The goal of this study was to determine to what extent MI acutely influences the motor unit recruitment of the lower extremities (LE) during jumping tasks influenced by the Stretch-Shortening Cycle (SSC). Methods: Thirteen subjects (Age x̄=20 years ± 1.5) participated in this study. A tri-axial accelerometer (Myotest, Sweden) was used to measure power output, height and velocity during the Counter-Movement Jump (CMJ) and Squat Jump (SJ). Subjects attended 2 sessions. The first was a familiarization and baseline jumping session where subjects were randomly assigned to one of two groups (treatment or control). The second was a post-test session. The treatment group received a MI cue, whereas the control group did not. Between each test and session, the treatment group performed a MI cue. Results: Independent samples t-tests using SPSS software showed there was no significance (p ≥ .05) between pre-test and post-test interventions found between groups. SJ Power (W/kg) p=.937; SJ Height (cm) p=.551; SJ Velocity (m/s) p=.738; CMJ Power (W/kg) p=.405; CMJ Height (cm) p=.958; CMJ Velocity (m/s) p=.366. Conclusion: The data indicated that the acute implementation of MI does not significantly affect jumping performance. Therefore, the use of MI does not have an acute impact on, or increase LE jumping parameters that would be utilized in rehabilitation, sports performance or settings that are subject to shorter periods of practice. Research has demonstrated other performance increases with greater periods of exposure to MI, thus we may conclude that prolonged periods of exposure to MI are necessary to evoke performance increases.